The island of Timor was split between Dutch and Portuguese halves, and Portugal was so far neutral in the Second World War, if only because Ferdinand Franco, the ruler of Fascist Spain, didn’t want to give Hitler a reason for occupying the Iberian peninsula. Nonetheless, the administrators of the Portuguese Far East colonies weren’t blind to Japanese atrocities and were sympathetic to the Allied cause. In accordance with a secret Dutch and Portuguese agreement, Australian troops occupied the island in January 1942, with the Portuguese governor taken “prisoner” to give the appearance of neutrality.

On 20 February, 1942, Imperial Japanese forces simultaneously landed on both the Dutch and Portuguese halves of Timor, with an airborne landing to capture the airfield. The defending “Sparrow Force”, a mixed formation of Australian and Dutch infantry, Australian commandos, and Timorese irregulars slaughtered the Japanese on the beaches and annihilated the airborne landings so thoroughly that the Japanese would never again attempt it in such numbers. But the Allied forces, out of respect for the Portuguese, didn’t cover all possible landing zones. A victorious fixed force defending a beach is still a fixed force, and within three days the overwhelming number of Japanese infantry, tanks, and aircraft, landed on the Portuguese half of the island, forced the Sparrow Force’s surrender. However, dozens of Australian commandos and Timorese irregulars escaped into the mountains to carry on resistance.

For the next six months, the commandos carried on a guerrilla war against the Japanese. The Japanese responded by slaughtering Dutch, Portuguese, and Timorese civilians, which only drove them to cooperate with the Australians. Australian and Dutch ships and planes ran supplies and replacements to the commandos, the sum total never exceeded 500. They tied down a division of Japanese, much needed elsewhere.

In the fall of 1942, the Japanese knew they needed to change: Timor was an unholy vortex sucking men, weapons, and material from the New Guinea campaign. They changed their tactics. They shipped reinforcements to Timor and ordered the Japanese troops there to separate the Australians and Timorese fighters from the population, and recruit Timorese civilians to inform on the resistance. A natural byproduct was an end to the atrocities, and a velvet glove handling to Portuguese and Timorese civilians.

The new Japanese approach worked, and the Allied commandos were forced into a smaller and smaller pocket of mountainous Portuguese Timor. On 10 February, 1943, nearly a year after the invasion, the last Australian and Dutch troops were evacuated from the island. They tied up nearly 30,000 much needed Japanese troops for almost a year.

The Japanese tactics were only a matter of convenience. Once the Japanese were sure the Allied troops were gone, they turned on the Timorese, Dutch, and Portuguese civilians. They slaughtered anyone suspected of assisting the commandos. By the beginning of March, 1943, more than 20,000 were murdered.